High value biological samples are often stored and processed using so-called SBS format racks containing a plurality of test tubes. Such racks may contain, for example, 96 test tubes in an array of 8 by 12 apertures designed to hold the tubes securely. The test tubes and their contents may be maneuvered in a processing system, for example between a cold store and various processing stations and may be required to be filled (partly or fully) or processed simultaneously or individually.
Conventionally, capping and de-capping has either been carried out by hand or else by means of a capping and de-capping unit one test tube at a time, either while they are still held in the rack or after they have been separated from the rack. This is not only tedious (particularly in the case of manual capping and de-capping), but also slow as it is usual for multiple tubes to require processing in the same way at the same time.
It is known to provide a linear array of capping and de-capping units to allow for the capping and de-capping of a row of tubes, but such systems have been bulky as a result of the dimensions of the drive mechanisms for the capping and de-capping units, the close spacing of the test tubes requiring the drive mechanisms of the capping and de-capping units to be remote from the capping and de-capping heads and disposed over a larger footprint than the rack because of their size.
EP 1882949 disclose a capping and de-capping apparatus having a test tube rack support for supporting a rack containing a plurality of capped test tubes in a given position. A head unit supports a two-dimensional array of capping and de-capping spindles, each of which includes a clutch and a capping and de-capping spigot or socket, the spindles being aligned with the test tube positions defined in the rack. A drive mechanism moves the tubes and the head unit relatively towards and away from one another in use, when a rack containing capped test tubes is disposed in the rack support, causing engagement and disengagement of the spigots or sockets with and from the tube caps. A spindle drive system provides simultaneous rotation of the spigots or sockets together after engagement with the caps, either to attach caps to the tubes or detach caps from the tubes. Ejection of the caps from the spigots is caused by moving an external net in the opposite direction to the spindle translational movement thereby detaching all sockets from all caps in one movement.